The British series Coupling is smart and competent and sophisticated and all about sex. Its cleverness just oozes out: every complex film-making, scene-arranging trick you can imagine is exploited for fun: multiple perspectives, an edited timeline, counting down to a moment from hours before and hours after, the presentation of an episode, bit by bit, as the characters discover more about what happened. This is demanding television; I can think of no U.S. counterpart.
Also, the writers love actors. They give the actors magnificent, funny, sad, twisty monologues - chances to show what they can do.
And, they stay with sex. Other matters come up, but within five minutes, we're back to sex. And sex is really funny and charming and exciting and worth talking about: that's the message. But sex isn't the horizon of the show, just its topic. The horizon is made visible in the theme song, and one gets glimpses of it from time to time in the episodes: "if you can't make your mind up, we'll never get started." Jolly sex may be at the center of the show, but commitment, getting on with things, having relationships and maybe babies is still always coming up, maybe more powerfully because the characters struggle so hard to keep that from coming up, to keep things silly.
It is rare to have a show make plausible the message: "Here is something really important that isn't the only thing or the most important thing." It takes artistic maturity.